骨髓基质细胞对SOD1转基因小鼠的作用及机制探讨

Effect and mechanism of marrow stromal cells within cerebrospinal fluid on SOD1 transgenic mice

目的研究脑脊液内移植小鼠骨髓基质细胞（MSCs）对铜锌超氧化物歧化酶1（SODI）转基因小鼠的作用及机制。方法将5×10^5MSCs经枕大池移植（8、10和12周龄时）到SODl转基因小鼠的脑脊液中。通过悬线试验和运动神经元计数来评估小鼠的疾病进展。应用免疫荧光染色观察15周龄SODl小鼠脊髓前角胶质细胞的活化。应用反转录一聚合酶反应检测MSCs神经营养因子mRNA的表达。结果鞘内移植MSCs能够改善SODl小鼠的运动行为，并保护运动神经元。MSCs鞘内移植明显减轻SODl小鼠脊髓前角小胶质细胞（52±7比38±7；F=69．3，P=0．02）和星形胶质细胞（79±9比63±9；F=40．7，P=0．03）的活化。另外，在炎症环境中，MSCs神经生长因子mRNA的表达明显增多（P〈0．05）。结论鞘内移植MSCs对SODl转基因小鼠有治疗作用，可能与减轻神经炎症和分泌神经生长因子发挥了神经保护作用有关。

Objective To explore the effect and mechanism of murine marrow stromal cells （MSCs） within eerebrospinal fluid （CSF） on Cu/Zn superoxide dismutase 1 （SOD1） transgenic mice. Methods A dose of 5 x 10^5 MSCs was injected into the CSF of SODI transgenic mice at the ages of 8, 10 and 12 weeks. Hanging wire test and motor neuron counts were used to assess disease progression of SOD1 mice. To examine the glial activation in murine lumbar spinal cord at 15 weeks of age, the sections were stained with antibody to CD1 lb and GFAP through immunohistochemistry. In vitro, mRNA expression of neurotrophin of MSCs was analyzed by reverse transcription-polymerase chain reaction （RT-PCR）. Results Compared with vehicle-treated mice, intrathecally transplanted MSCs enhanced motor performance and decreased motor neuron loss. An intrathecal injection of MSCs inhibited microglial （ 52 ± 7 vs 38± 7 ; F = 69.3, P =0. 02） and astrocyte（79 ±9 vs 63±9; F=40. 7, P =0. 03） activity in lumbar spinal cord at the age of 15 weeks of age. MSCs cultured in an inflammatory environment expressed a higher mRNA level of neurotrophin（ P 〈 0. 05 ）. Conclusion A CSF administration of MSCs has therapeutic effects on SOD1 mice. And the meditation of MSCs may be achieved through inhibiting neuroinflammation and secreting a variety of trophic factors.